Person 1: It's so hard to choose whether to fap with my left or my right hand...
Person 2: You can use both???
Person 1: You can't?
Person 2: Dude, you're so lucky you're ambifaptrous.
Marked by the ability to masturbate easily with either hand. Particularly applicable to males.
"I've beentrying to jerk off with my left hand recently to change things up, but it just hasn't worked for me. I wish I was ambimasturbous like Dave. That guy's a wank warrior."
Guy 1: I burned my right hand pretty bad yesterday.
Guy 2: That sucks man, guess you won't be spanking it for a while.
Guy 1: Nah dude, I can still do it with my left hand. I'm ambifapstrous.